I remember both primary and secondary school reading assignments, neither instilled a love of reading because the books generally just sucked. In primary school (1991–2000) we read books such as: “The Kay”, “Where the Red Fern Grows”, “Sadako and the Thousand Paper Cranes”, “David”, and importantly, the selection of books we could choose from, wasn't good. In grade 6, I got in trouble for bringing a book from the town library, that my teach, Mrs Rosey, found inappropriate due to the plot / theme. I don't remember the name of the series, but it was medieval fantasy, and it has three books, all pretty good from memory, but I wasn't allowed to read them for my book reports. Then there was the time I bought in an autobiography from Tim Allen, and was told you can't write a book report on a biography, was never told why, and for the record, you can. I left primary school with the incorrect assumption that reading was boring, stupid and lame, the typical opinion of many students.
Secondary school didn't get much better, apart from the “classics” like “The Great Gatsby”, and “The Pearl”, we read “Hatecht”, “Crab”, and many others, I'm really blanking on them right now. I remember none of them caught my attention or gave me a want to read more. During open reading period the book I brought was considered inappropriate, again, due to the plot / theme. It was a book about dark, and I mean dark, BDSM themes, all fictional. I still have the collection on my bookshelf in the basement. The school, VP, P and English Teacher tried to lecture me about why the book was inappropriate, and of course failed because they promoted “R&J”, a play about pseudo-necro-paedophilia. They actually tried to convince me a book about a pre-teen making out with a different dead pre-teen was someone how the height of literature. The book I brought, which was about a female slave serving a house, wasn't trash. At least the character in my book was an adult, and didn't violate the dead body of another.
Then there were free writing periods, where again, I got in trouble for plots / themes that my teachers thought were inappropriate. I went to catholic school, where the primary them of the Bible is basically God raping Mary, to birth himself as human, so he can put on a grandstanding S&M session to forgive himself, from himself to himself, for being a shitty engineer (basically a Rust evangelist). My stores didn't include rape, S&M, or an inability to grasp the basic concept of morality or ethics, so why were they inappropriate? I remember Ms Brown trying to explain why the story I submitted was inappropriate, but, never convinced me.
Maybe the numbers are falling because adults pushed, and are pushing low-quality trash, as the gold standard, well, eliminating choice, freedom, and exploration. I also took creative writing in University, as an elective, but we won't go into that, the teacher was mentally ill, and not slightly, she was a boot stomping far-left feminist, who thought the Middle Ages never happened.
When I started to enjoy reading again, when I got to pick the books I wanted to read, without the expectation that if I didn't like them, I was unfit to read them in the first place. If you want to make kids love reading, give them a large selection, across all possible and plusable, legal, themes/plots. Be prepared to discuss the books properly, without bias, and with an open mind. Imagine if a white student brough a book about a fictional KKK group, commiting acts of hate, and violence, prompted as positive. If a black teacher wouldn't engage, openly and willingly with that book and student, that teacher is the problem. If a kid brings in an Anne Rice novel, about extremely dark BDSM themes, and you don't feel comfortable with the kid reading it, again, thats your problem.